Cutting apparatus



July 27, 1948. s. c. NELSON summe APPARATUS Filed May 24, 1944 INVENTOR.

314., ATTORNEY ultimate characteristics.

Patented July 27, 1948 UN ED STATES PATENT OFFICE y "i 1,440,091

' I cu'rmc APPARATUS Seddon'C. Nelson, Front Royal, -Va., assixnor toAmerican Viscose Corporation, Wilmington,

DeL, a corporationof Delaware Application May 24, 1944, Serial No.537,030

This invention relates the production of staple fibers of rayon andother synthetic filamentary material and is particularly concerned witha process and apparatus for'treating staple fiber during its manufactureto facilitate its subsequent processing and to improve its In manyprocedures for cutting continuous filamentary material to staple fibers,a continuous filamentary materialproceeds to the cutting a device as aheavy bundle such as in the form of a rope or tow of approximatelycircular, elliptical, or rectangular cross-section, frequentlycontaining many thousands of filaments and this bundle is then cut todiscontinuous lengths" thereby forming numerous individual bunches orclumps of fibers. These clumps then proceed either to opening, carding,spinning and like processes or to subsequent stages of treatment, suchaswashi 18, bleaching, and then to the opening and other at the 8'(laims. (01. 19'-66) to cutting apparatus for i rugations. serrations,notches and the like. The

' condition through the apparatus of the present invention so that thefibers cutare in a somewhat softened or plastic condition, there isobtained the additional desirable characteristic ofcrimpinesssimultaneously with the opening operation so that a subsequent separates'teprof crimping is unnecessary to better adapt such staple fibers forsubsequent textile processes, such 7 as in carding and spinning. In thisarrangement, crimping is obtained along with the opening provided thetow is in a wet or somewhat plastic condition at the time of treatmentIn the drawing, illustrative of the invention, Figure 1 is a plan viewof one embodiment of the invention, associated with a staple fibercutter of the Beria type applying a rotatable mem her for delivering thecontinuous filamentary tow to the cutting element by centrifugal force.

Figure 2'is aface view of the knife of Figure 1, Figure 3 is anelevation of a second embodiment of the invention, associated with astaple fiber cutter in which the knives are movable, Figure 4 is a faceview of'a modified form of .knife,

a side view' of the knife of Figure 4,

Figure 5 is and Figures and 7 are side and face views respectively ofanother modification.

Figures 1 and 2 show one form of apparatus embodying the invention. Asthere shown, an obstruction 2' having a serrated surface 31 is arrangedupon the back of the knife 4 to receive clumps 5 of staple fibers thrownthereagalnst. As shown, the knife l is employed with a Beria type ofstaple fiber cutter which normally throws the clumps of fibers cuttherefrom, at a fairly high velocity. This cutter comprises a shearofthe disk into cutting relationship. with the stationary knife 4 (or aplurality thereof positioned about the periphery of the disk). Theserrated surface 3 of the obstruction is arranged in the 'path'oftravelof the fiber clumps 5 thrown from the disk 6 so that they areimpacted thereupon and splatter acrossv the surface thereof, Thissplattering'is accentuated by the indentations of the surface so thatconsiderable opening is accomplished thereby. The tow of continuousfilamentary material may be in a plastic condition at the time ofcutting so that theserrated surface ,3 accomplishes a certain amount ofcrimping simultaneously with the opening of the clumps.

When the fiber product is in a plastic condition, it may be desirable toassist its removal from the surface 3, which ordinarily would occurreadily and rapidly by momentumor gravity, by means of a fluid jet 9which is shown (Figure 2) above the indented surface of the obstructionwith a long orifice adapted to sweep the entire surface.

Figure, 3 shows a modified arrangement in which the obstruction 2a isprovided on each of a number of rapidly rotating knives l0 carried bythe shaft l I. this form of device, the condented obstruction 2b inwhich the serrations so in slope back from one side to the other of theknife II. This arrangement has a further advantage of directing the cutfibers downward.

Figures 6 and 7 show a further modification of the obstruction 2c inwhich the indentations 3c are disposed generally perpendicular to aplane parallel to the blade and shank of the knife ll.

The indented surface of the projection or obstruction may be arranged atvarious angles other than those shown in the-drawing; Such variationyields somewhat distinct opening characteristics and when a wetfilamentary material is being operated upon they provide some variationof crimping characteristics. The form of indentations may bevarious,,the serrated and stepped modifications shown in the drawingbeing merely illustrative. The dimensions of the indentations mayvary'widely. However. certain dimensions are preferably smaller thanparticular dimensions of the clumps of staple fibers being cut, dependsoing upon the manner in which the clumps strike the indented surface. Forexample, in the arrangement of Figures 1 and 2, where the length of thefiber clumps strikes transversely of the serrations, the "pitch of theserrations should 3!! be smaller than the length of the clump, so that aclump bears against a plurality of the serrations. In the arrangement ofFigures 6 and 7 where the steps shear oil portions of the clump,

the height of the steps facing the clumps should 40 be smaller than thebundle thickness or diameter so that a plurality of shearings areefiected upon each clump. v

As stated above the operation of the cutting devices of this inventionhas as its main purpose the opening of the staple fiber clumps when itis performed upon a dry tow so that subsenuent processing can be moreefllciently performed upon the product. However, when the invention isapplied to the handling of a: wet continuous filaprising a stationaryknife having a cutting edge, a member co-operating therewith to guidethe leading end of the material into cutting position,

inentary material, it has the function not only of opening the fiberclumps but of crimping the fibers within the clumps. Previous proceduresinvolving the cutting of staple fibers from a continuous filamentary towin a wet condition ordinarily sent theclu'mps obtained at the cuttingstep through wet treatment processes, such as washing, bleaching andthen drying. It has been found that the application of the devices ofthis invention to the production of staple fiber from being extremelysimple and inexpensive modifica- 7n tions of the knives alone.

While preferred embodiments have been disclosed, the description isintended to be illustrative only, and it is to be understood thatchanges and variation may be made without departing 76 In thisarrangement the 6 from the spirit and scope of the invention as definedby the appended claims.

I claim:

1. A device for cutting continuous filamentary material to fibers ofdiscontinuous lengths comprising a cutting member having a cutting edge,a memberco-operating therewith to guide the leading end of the materialinto cutting position, means for imparting a high velocity to one of themembers relative to the other in a direction gen-- erally transverse ofthe cutting edge, and a pro- .lection on the cutting member having anindented surface spaced back of the. cutting edge and away projectionthereon having an indented surface spaced back of the cutting edge withits indentations disposed to provide longitudinal ridges lying in planeswhich are generally parallel to the cutting edge, said surface beinginclined to face the tion generally transverse of the cutting edge, and

a projection on the knife havingan indented surface spaced back of thecutting edge and away from the guiding member in a direction transverseof the direction of the "cutting edge and arranged to face theleadingend of the material when the latter is near the cutting positionso,

that collision of the fibers therewith occurs upon cutting actionwhereby an opening and crimping action is exerted upon the fibers asthey collide.

' 4. A device for cutting continuous filamentary material to fibers ofdiscontinuous lengths commeans for imparting a high velocity to thecooperating member in a direction generally transverse of the cuttingedge,'and a projection on the knife having an indented surface spacedback of the cutting edge and away from the guiding member in a directiontransverse of the direction of the cutting edge and arranged to face theleading end of the material when the latter is near the cutting positionso that collision of the fibers therewith occurs upon cutting actionwhereby an opening and crimping action is exerted upon the as fibers asthey collide.

5. In combination, a centrifugal cutting device having a stationaryknife having a cutting edge, a rotary element for feeding a filamentarybundle endwise and outwardly into cutting engagement transverse of theknife, a projection on the back of the knife away from the rotaryelement having an indented surface spaced back of thecutting edge in adirection transverse of the direction of the cutting edge, said indentedsurface facing the portion of the bundle fed outwardly of the rotary 6.A device for cutting continuous filamentary material to fibers ofdiscontinuous lengths comprising a cutting member having a cutting edge,a member co-operating therewith to guide the leading end of the materialinto cutting position, means for imparting a high velocity to one of themembers relative to the other in a direction gen erally transverse ofthe cutting edge, a projection on the cutting member having an indentedsurface spaced back of the cutting edge and away from the guiding memberin a direction transverse of the direction of the cutting edge andarranged to face the leading end of the material when the latter is nearthe cutting position so that collision of the fibers therewith occursupon cutting action whereby an opening and crimping action is exertedupon the fibers as they collide, and means for removing fibers from theindented surface.

7. A device for cutting continuous filamentary material to fibers ofdiscontinuous lengths comprising a cutting member having a cutting edge,a member co-operating therewith to guide the I leading end of thematerial into cutting position,

means for imparting a high velocity to one of the members relative tothe other in a direction generally transverse of the cutting edge, aprojection on the cutting member having an indented surface spaced backof the cutting edge and away from the guiding member in a directiontransverse of the direction of the cutting edge and arranged to'f'acethe leading end of the material when the latter isnear the cuttingposition so that collision of the fibers therewith occurs upon cuttingaction whereby an opening and crimping action is exerted upon the fibersas they collide,

and fluid means for blowing fibers from the indented surface.

8. In combination, a centrifugal cutting device having a, stationaryknife having a cutting edge, a rotary element for feeding a filamentarybundle 'endwise and outwardly into cutting engagement transverse of theknife, a projection on the back of the knife away from the rotaryelement having an indented surface spaced back of the cutting edge in adirection transverse of the direction of the cutting edge, said indentedsurface facing the portion of the bundle fed outwardly of the rotaryelement, means for rotating the element at high speed to impel the cutfiber bundles against the indented surface of the projection on the backof the knife whereby an opening and crimping action is exerted upon thefibers as they collide, and fluid means for blowing fibers from theindented surface.

SEDDON C. NELSON.

REFERENCES CITED The following references are file of this patent:

UNITED STATES PATENTS of record in the

